From 46c1b6eaee4ca00c256c5c403c6d6bfeaf3b63f8 Mon Sep 17 00:00:00 2001 From: Johannes Erdfelt Date: Sun, 25 Mar 2012 02:06:01 +0800 Subject: Add multi-process support for API services Implements blueprint multi-process-api-service This is based on Huang Zhiteng's patch. This patch adds support for running services as multiple processes. This is primarily intended to be used with the API service as a way to provide more concurrency than eventlet can sometimes provide. A SIGTERM or SIGINT signal will cause the parent process to gracefully terminate the child processes, allowing them to finish processing the requests currently being processed. The parent will wait for the children to finish before exiting. Change-Id: Ie6d6802626eb42d5e64c4167be363fbf6cea2a1b --- nova/wsgi.py | 52 +++++++++++++++++++++++----------------------------- 1 file changed, 23 insertions(+), 29 deletions(-) (limited to 'nova/wsgi.py') diff --git a/nova/wsgi.py b/nova/wsgi.py index 436f4df2e..a02fdcc18 100644 --- a/nova/wsgi.py +++ b/nova/wsgi.py @@ -44,8 +44,8 @@ class Server(object): default_pool_size = 1000 - def __init__(self, name, app, host=None, port=None, pool_size=None, - protocol=eventlet.wsgi.HttpProtocol): + def __init__(self, name, app, host='0.0.0.0', port=0, pool_size=None, + protocol=eventlet.wsgi.HttpProtocol, backlog=128): """Initialize, but do not start, a WSGI server. :param name: Pretty name for logging. @@ -53,47 +53,37 @@ class Server(object): :param host: IP address to serve the application. :param port: Port number to server the application. :param pool_size: Maximum number of eventlets to spawn concurrently. + :param backlog: Maximum number of queued connections. :returns: None - + :raises: nova.exception.InvalidInput """ self.name = name self.app = app - self.host = host or "0.0.0.0" - self.port = port or 0 self._server = None - self._socket = None self._protocol = protocol self._pool = eventlet.GreenPool(pool_size or self.default_pool_size) - self._logger = logging.getLogger("eventlet.wsgi.server") + self._logger = logging.getLogger("nova.%s.wsgi.server" % self.name) self._wsgi_logger = logging.WritableLogger(self._logger) - def _start(self): - """Run the blocking eventlet WSGI server. - - :returns: None + if backlog < 1: + raise exception.InvalidInput( + reason='The backlog must be more than 1') - """ - eventlet.wsgi.server(self._socket, - self.app, - protocol=self._protocol, - custom_pool=self._pool, - log=self._wsgi_logger) + self._socket = eventlet.listen((host, port), backlog=backlog) + (self.host, self.port) = self._socket.getsockname() + LOG.info(_("%(name)s listening on %(host)s:%(port)s") % self.__dict__) - def start(self, backlog=128): + def start(self): """Start serving a WSGI application. - :param backlog: Maximum number of queued connections. :returns: None - :raises: nova.exception.InvalidInput - """ - if backlog < 1: - raise exception.InvalidInput( - reason='The backlog must be more than 1') - self._socket = eventlet.listen((self.host, self.port), backlog=backlog) - self._server = eventlet.spawn(self._start) - (self.host, self.port) = self._socket.getsockname() - LOG.info(_("Started %(name)s on %(host)s:%(port)s") % self.__dict__) + self._server = eventlet.spawn(eventlet.wsgi.server, + self._socket, + self.app, + protocol=self._protocol, + custom_pool=self._pool, + log=self._wsgi_logger) def stop(self): """Stop this server. @@ -105,7 +95,11 @@ class Server(object): """ LOG.info(_("Stopping WSGI server.")) - self._server.kill() + + if self._server is not None: + # Resize pool to stop new requests from being processed + self._pool.resize(0) + self._server.kill() def wait(self): """Block, until the server has stopped. -- cgit